36th International Conference on Coastal Engineering 2018, Baltimore Submarine Mass Failure: Wave generation by granular slides
Frederic M. Evers, Helge Fuchs, David Vetsch, Robert M. Boes ETH Zurich, Laboratory of Hydraulics, Hydrology and Glaciology (VAW)
| 1
Motivation
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Sentinel [ESA/Copernicus [ESA/Copernicus
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Motivation
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Sentinel [ESA/Copernicus [ESA/Copernicus
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Motivation
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Sentinel [ESA/Copernicus [ESA/Copernicus
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Motivation
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Sentinel [ESA/Copernicus [ESA/Copernicus
| 5 Motivation
[Wikimedia Commons]
[Wikimedia Commons]
]
Sentinel [ESA/Copernicus [ESA/Copernicus
| 6 Lake Geneva 563 CE
Geneva CH Lausanne
Montreux
Possible Rockfall FR Rhône Valley
[Kremer et al. 2012] Geneva
| 7 Lake Lucerne 1601 CE
Lucerne Weggis slide 2220 BP 1601 CE
1687 CE 2015]
Gersau basin slide
Anselmetti & &
Earthquake magnitude 5.9 on 16 September 1601
Hilbe [
| 8 Lake Lucerne 1601 CE
Historical records:
Reflection seismic profiles In the Küssnacht Basin the waves threw entire ships out of the lake and deposited them "50 steps from the shore and two
halberds high" 2011]
above the normal water et al.
level on land.
Hilbe [
[Wikimedia Commons]
| 9 Lake Tsunamis – Interdisciplinary approach
Seismic hazard Limnogeology Seismology
Marine Wave geotechnics processes
Tsunami Hazard Assessment
| 10 Overview
. Motivation: Lake Tsunamis . Experimental setup . Results . Conclusions . Outlook
| 11 Lake Tsunamis – Wave processes
| 12 Lake Tsunamis – Wave processes
Experiments
| 13 Experimental setup
Δx = 0.8 m
Channel length ≈ 8 m
| 14 Experimental setup – Parameter range
α 30, 45, 60 [°]
dg 2 - 8 [mm]
ls 0.11 - 0.44 [m]
ms 5 - 20 [kg]
ds 0.11 - 0.31 [m] h 0.7 - 0.87 [m]
| 15 Results – Side camera
10 kg
0.7 m 0.5 m
30°
| 16 Results – Side camera α = 30°
| 17 Results – Side camera α = 60°
| 18
Results – Ultrasonic distance sensors (UDS)
2017]
Kislig [
η/h : relative water surface displacement t(g/h)0.5 : relative time
| 19 Results – Governing parameters
Governing parameters
ms : slide mass
ds : submergence α : bank inclination angle h : stillwater depth
Wave characteristics
ac1 : wave crest amplitudes
at1 : wave trough amplitude
2 Dimensionless governing parameters: Ms = (ρg−ρw)Vs/(ρwbh ) : relative slide mass
Dc = ds/h : relative submergence
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Results – Maximum first wave crest and trough amplitudes
2017]
Kislig [
| 21
Results – Wave amplitude decay
2017]
Kislig [
| 22 Conclusions . Submarine landslide tsunamis also occur in lakes . Earthquakes are assumed the primary trigger in Switzerland . Modelling the entire process chain is highly challenging . Hydraulic experiments were conducted in a wave channel . Empirical equations were established for unidirectional wave propagation . Physical processes may not be properly simulated in laboratories
Outlook: Benchmark for numerical models Particle Image Velocimetry (PIV) measurements
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Outlook: PIV measurements – work in progress
2018]
Landolt [
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Outlook: PIV measurements – work in progress
2018]
Landolt [
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Outlook: PIV measurements – work in progress
2018]
Landolt [
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Outlook: PIV measurements – work in progress
2018]
Landolt [
| 27 Frederic M. Evers Acknowledgements: [email protected]
ETH Zurich Laboratory of Hydraulics, Hydrology and Glaciology (VAW)
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